<!DOCTYPE html><html lang="zh-Hans"><head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1"><meta name="description" content="iOS绘图与动画系列 CAShapeLayer（三）"><meta name="keywords" content="iOS,动画,绘图"><meta name="author" content="kyren"><meta name="copyright" content="kyren"><title>iOS绘图与动画系列 CAShapeLayer（三） | Kyren's Blog</title><link rel="shortcut icon" href="/melody-favicon.ico"><link rel="stylesheet" href="/css/index.css?version=1.9.0"><link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/font-awesome@latest/css/font-awesome.min.css?version=1.9.0"><meta name="format-detection" content="telephone=no"><meta http-equiv="x-dns-prefetch-control" content="on"><link rel="dns-prefetch" href="https://cdn.jsdelivr.net"><link rel="dns-prefetch" href="https://hm.baidu.com"><script>var _hmt = _hmt || [];
(function() {
  var hm = document.createElement("script");
  hm.src = "https://hm.baidu.com/hm.js?cf87fcdbd9ab7cf93d894f7c219ae78f";
  var s = document.getElementsByTagName("script")[0]; 
  s.parentNode.insertBefore(hm, s);
})();</script><meta http-equiv="Cache-Control" content="no-transform"><meta http-equiv="Cache-Control" content="no-siteapp"><script src="https://v1.hitokoto.cn/?encode=js&amp;charset=utf-8&amp;select=.footer_custom_text" defer></script><script>var GLOBAL_CONFIG = { 
  root: '/',
  algolia: undefined,
  localSearch: {"path":"search.xml","languages":{"hits_empty":"找不到您查询的内容:${query}"}},
  copy: {
    success: '复制成功',
    error: '复制错误',
    noSupport: '浏览器不支持'
  },
  hexoVersion: '6.2.0'
} </script><meta name="generator" content="Hexo 6.2.0"></head><body><i class="fa fa-arrow-right" id="toggle-sidebar" aria-hidden="true"></i><div id="sidebar" data-display="true"><div class="toggle-sidebar-info text-center"><span data-toggle="切换文章详情">切换站点概览</span><hr></div><div class="sidebar-toc"><div class="sidebar-toc__title">目录</div><div class="sidebar-toc__progress"><span class="progress-notice">你已经读了</span><span class="progress-num">0</span><span class="progress-percentage">%</span><div class="sidebar-toc__progress-bar"></div></div><div class="sidebar-toc__content"></div></div><div class="author-info hide"><div class="author-info__avatar text-center"><img src="https://avatars.githubusercontent.com/u/5827823?v=4"></div><div class="author-info__name text-center">kyren</div><div class="author-info__description text-center">huluo的技术博客</div><div class="follow-button"><a target="_blank" rel="noopener" href="https://github.com/huluo666">Follow Me</a></div><hr><div class="author-info-articles"><a class="author-info-articles__archives article-meta" href="/archives"><span class="pull-left">文章</span><span class="pull-right">239</span></a><a class="author-info-articles__tags article-meta" href="/tags"><span class="pull-left">标签</span><span class="pull-right">41</span></a><a class="author-info-articles__categories article-meta" href="/categories"><span class="pull-left">分类</span><span class="pull-right">29</span></a></div><hr><div class="author-info-links"><div class="author-info-links__title text-center">Links</div><a class="author-info-links__name text-center" target="_blank" rel="noopener" href="http://192.168.2.212:9090/">Jira</a><a class="author-info-links__name text-center" target="_blank" rel="noopener" href="http://192.168.2.212:8090/">Confluence</a><a class="author-info-links__name text-center" target="_blank" rel="noopener" href="http://bloc.leniugame.com/">Leniu</a></div></div></div><div id="content-outer"><div class="no-bg" id="top-container"><div id="page-header"><span class="pull-left"> <a id="site-name" href="/">Kyren's Blog</a></span><i class="fa fa-bars toggle-menu pull-right" aria-hidden="true"></i><span class="pull-right menus">   <a class="site-page" href="/">主页</a><a class="site-page" href="/essay">随笔</a><a class="site-page" href="/archives">归档</a><a class="site-page" href="/tags">标签</a><a class="site-page" href="/categories">分类</a><a class="site-page" href="/about">关于</a></span><span class="pull-right"><a class="site-page social-icon search"><i class="fa fa-search"></i><span> 搜索</span></a></span></div><div id="post-info"><div id="post-title">iOS绘图与动画系列 CAShapeLayer（三）</div><div id="post-meta"><time class="post-meta__date"><i class="fa fa-calendar" aria-hidden="true"></i> 2016-04-08</time></div></div></div><div class="layout" id="content-inner"><article id="post"><div class="article-container" id="post-content"><p><code>CAShapeLayer</code>是一个通过矢量图形而不是bitmap来绘制的图层子类。你指定诸如颜色和线宽等属性，用<code>CGPath</code>来定义想要绘制的图形，最后<code>CAShapeLayer</code>就自动渲染出来了。当然，你也可以用Core Graphics直接向原始的<code>CALyer</code>的内容中绘制一个路径，相比直下，使用<code>CAShapeLayer</code>有<code>以下一些优点</code>：</p>
<ul>
<li><p>渲染快速。<code>CAShapeLayer</code>使用了<code>硬件加速</code>，绘制同一图形会比用Core Graphics快很多。</p>
</li>
<li><p>高效使用内存。一个<code>CAShapeLayer</code>不需要像普通<code>CALayer</code>一样创建一个寄宿图形，所以无论有多大，都不会占用太多的内存。</p>
</li>
<li><p>不会被图层边界剪裁掉。一个<code>CAShapeLayer</code>可以在边界之外绘制。你的图层路径不会像在使用Core Graphics的普通<code>CALayer</code>一样被剪裁掉（如我们在第二章所见）。</p>
</li>
<li><p>不会出现像素化。当你给<code>CAShapeLayer</code>做3D变换时，它不像一个有寄宿图的普通图层一样变得像素化。</p>
<p>来源：<a target="_blank" rel="noopener" href="http://www.kancloud.cn/manual/ios/97790"><strong>ios核心动画高级技巧</strong></a></p>
</li>
</ul>
<p><strong>为什么优先选择CAShapeLayer绘图？</strong></p>
<blockquote>
<p>CoreGraphics不就可以绘制我们需要的图形，为什么还需要CAShapeLayer来绘图，这是由于UIView的drawRect是用的CoreGraphics框架,是由Cpu进行动画渲染,性能消耗大,而CAShapeLayer属于CoreAnimation框架,其实走的是Gpu动画渲染,使用硬件加速,节省性能，速度也快的多。</p>
</blockquote>
<p>基于CAShapeLayer以上优点，以及之前所说的UIBezierPath路径绘制的优势，结合2者用它来生成我们想要的各种图形是最合适不过了。</p>
<ol>
<li>CAShapeLayer是继承至CALayer,可以使用CALayer的所有属性。</li>
<li>CAShapeLayer有一个属性path，类型为CGPathRef，而UIBezierPath就是对CGPathRef类型的封装，因此，这两者配合起来使用才可以！</li>
</ol>
<p><strong>相关属性</strong></p>
<figure class="highlight markdown"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br></pre></td><td class="code"><pre><span class="line">path：不像大多数的动画属性，path不支持隐式动画。</span><br><span class="line">fillColor：填充path的颜色，或无填充。默认为不透明黑色。动画的。</span><br><span class="line">fillRule：填充path的规则。选项是非零和偶奇。默认为非零。</span><br><span class="line">      NSString <span class="emphasis">*const kCAFillRuleNoneZero;</span></span><br><span class="line"><span class="emphasis">      NSString *</span>const kCAFillRuleEvenOdd;</span><br><span class="line">lineCap：线端点类型</span><br><span class="line">      NSString <span class="emphasis">*const kCALineCapButt; //默认 顶格</span></span><br><span class="line"><span class="emphasis">      NSString *</span>const kCALineCapRound;//圆角</span><br><span class="line">      NSString <span class="emphasis">*const kCALineCapSquare;//方角</span></span><br><span class="line"><span class="emphasis">lineDashPattern：线性模版，这是一个NSNumber的数组，索引从1开始记，奇数位数值表示实线长度，偶数位数值表示空白长。</span></span><br><span class="line"><span class="emphasis">lineDashPhase：线型模版的起始位置。</span></span><br><span class="line"><span class="emphasis">lineJoin：线连接类型。</span></span><br><span class="line"><span class="emphasis">       NSString *</span>const kCALineJoinMiter;//默认 尖角</span><br><span class="line">       NSString <span class="emphasis">*const kCALineJoinRound;//圆滑</span></span><br><span class="line"><span class="emphasis">       NSString *</span>const kCALineJoinBevel;//切割平行</span><br><span class="line">lineWidth：线宽，用点表示单位。可动画。</span><br><span class="line">miterLimit：最大斜接长度。斜接长度指的是在两条线交汇处和外交之间的距离。只有lineJoin属性为kCALineJoinMiter时miterLimit才有效。边角的角度越小，斜接长度就会越大。为了避免斜接长度过长，我们可以使用miterLimit属性。如果斜接长度超过miterLimit的值，边角会以lineJoin的“bevel”即kCALineJoinBevel类型来显示。</span><br><span class="line"></span><br><span class="line">strokeColor：用来设置形状的线的颜色，可动画。如果设置为nil就表示没有颜色。</span><br><span class="line">strokeStart和strokeEnd：部分绘线。都是0.0～1.0的取值范围。经常被用来制作动画效果。</span><br></pre></td></tr></table></figure>
<p><a target="_blank" rel="noopener" href="http://blog.csdn.net/cuixiping/article/details/7848369">理解SVG的图形填充规则</a></p>
<p><strong>绘制步骤</strong></p>
<figure class="highlight swift"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br></pre></td><td class="code"><pre><span class="line"><span class="operator">-</span> (void)drawRect:(<span class="type">CGRect</span>)rect &#123;</span><br><span class="line">    <span class="comment">// Drawing code</span></span><br><span class="line">    <span class="comment">//1、创建BezierPath对象（有类方法与实例方法，具体查看Api）</span></span><br><span class="line">    <span class="type">UIBezierPath</span> <span class="operator">*</span>path <span class="operator">=</span> [<span class="type">UIBezierPath</span> bezierPathWithRect:<span class="type">CGRectMake</span>(<span class="number">20</span>, <span class="number">20</span>, <span class="number">100</span>, <span class="number">100</span>)];</span><br><span class="line">    </span><br><span class="line">    <span class="comment">//2、创建CAShapeLayer对象并设置相关属性</span></span><br><span class="line">    <span class="type">CAShapeLayer</span> <span class="operator">*</span>shapeLayer <span class="operator">=</span> [<span class="type">CAShapeLayer</span> layer];</span><br><span class="line">    shapeLayer.strokeColor <span class="operator">=</span> [<span class="type">UIColor</span> redColor].<span class="type">CGColor</span>;</span><br><span class="line">    shapeLayer.fillColor <span class="operator">=</span> [<span class="type">UIColor</span> clearColor].<span class="type">CGColor</span>;</span><br><span class="line">    shapeLayer.lineWidth <span class="operator">=</span> <span class="number">5</span>;</span><br><span class="line">    shapeLayer.lineJoin <span class="operator">=</span> kCALineJoinRound;</span><br><span class="line">    shapeLayer.lineCap <span class="operator">=</span> kCALineCapRound;</span><br><span class="line">    </span><br><span class="line">    </span><br><span class="line">    <span class="comment">//3、将贝塞尔路径UIBezierPath（OC）转换为C语言CGPathRef赋值给shapeLayer.path</span></span><br><span class="line">    shapeLayer.path <span class="operator">=</span> path.<span class="type">CGPath</span>;</span><br><span class="line">    </span><br><span class="line">    <span class="comment">//4、添加到相应layer层中显示</span></span><br><span class="line">    [<span class="keyword">self</span>.layer addSublayer:shapeLayer];</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>



<p><strong>画圆</strong></p>
<figure class="highlight swift"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="operator">-</span> (void)drawRect:(<span class="type">CGRect</span>)rect &#123;</span><br><span class="line">	    <span class="comment">//1、创建BezierPath对象</span></span><br><span class="line">       <span class="type">UIBezierPath</span>  <span class="operator">*</span>circleBezierPath <span class="operator">=</span> [<span class="type">UIBezierPath</span> bezierPathWithOvalInRect:<span class="type">CGRectMake</span>(<span class="number">50</span>, <span class="number">350</span>, <span class="number">100</span>, <span class="number">100</span>)];<span class="comment">//在区域内绘制椭圆曲线</span></span><br><span class="line"></span><br><span class="line">        <span class="comment">//2、创建CAShapeLayer对象并设置相关属性</span></span><br><span class="line">        <span class="type">CAShapeLayer</span>  <span class="operator">*</span>circleShapeLayer <span class="operator">=</span> [<span class="type">CAShapeLayer</span> layer];</span><br><span class="line">        [circleBezierPath setLineWidth:<span class="number">1</span>];</span><br><span class="line">        [circleShapeLayer setStrokeColor:[<span class="type">UIColor</span> redColor].<span class="type">CGColor</span>];</span><br><span class="line">        [circleShapeLayer setFillColor:[<span class="type">UIColor</span> blackColor].<span class="type">CGColor</span>];</span><br><span class="line">        [circleShapeLayer setBorderWidth:<span class="number">1</span>];</span><br><span class="line">    </span><br><span class="line">        <span class="comment">//3、将贝塞尔路径UIBezierPath（OC）转换为C语言CGPathRef赋值给shapeLayer.path</span></span><br><span class="line">        [circleShapeLayer setPath:circleBezierPath.<span class="type">CGPath</span>];</span><br><span class="line">        [<span class="keyword">self</span>.layer addSublayer:circleShapeLayer];</span><br><span class="line"> &#125;</span><br></pre></td></tr></table></figure>









</div></article><div class="post-copyright"><div class="post-copyright__author"><span class="post-copyright-meta">文章作者: </span><span class="post-copyright-info"><a href="mailto:undefined">kyren</a></span></div><div class="post-copyright__type"><span class="post-copyright-meta">文章链接: </span><span class="post-copyright-info"><a href="http://huluo666.gitee.io/2016/04/08/iOS绘图与动画系列 CAShapeLayer（三）/">http://huluo666.gitee.io/2016/04/08/iOS绘图与动画系列 CAShapeLayer（三）/</a></span></div><div class="post-copyright__notice"><span class="post-copyright-meta">版权声明: </span><span class="post-copyright-info">本博客所有文章除特别声明外，均采用 <a target="_blank" rel="noopener" href="https://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA 4.0</a> 许可协议。转载请注明来自 <a href="http://huluo666.gitee.io">Kyren's Blog</a>！</span></div></div><div class="post-meta__tag-list"><a class="post-meta__tags" href="/tags/iOS-%E5%8A%A8%E7%94%BB-%E7%BB%98%E5%9B%BE/">iOS,动画,绘图</a></div><nav id="pagination"><div class="prev-post pull-left"><a href="/2016/04/10/html%E6%95%99%E7%A8%8B/"><i class="fa fa-chevron-left">  </i><span>html笔记</span></a></div><div class="next-post pull-right"><a href="/2016/04/08/iOS%E7%BB%98%E5%9B%BE%E4%B8%8E%E5%8A%A8%E7%94%BB%E7%B3%BB%E5%88%97%20Animation%EF%BC%88%E5%9B%9B%EF%BC%89/"><span>iOS绘图与动画系列 Animation（四）</span><i class="fa fa-chevron-right"></i></a></div></nav></div></div><footer><div class="layout" id="footer"><div class="copyright">&copy;2022 By kyren</div><div class="framework-info"><span>驱动 - </span><a target="_blank" rel="noopener" href="http://hexo.io"><span>Hexo</span></a><span class="footer-separator">|</span><span>主题 - </span><a target="_blank" rel="noopener" href="https://github.com/Molunerfinn/hexo-theme-melody"><span>Melody</span></a></div><div class="footer_custom_text">hitokoto</div><div class="busuanzi"><script async src="//busuanzi.ibruce.info/busuanzi/2.3/busuanzi.pure.mini.js"></script><span id="busuanzi_container_page_pv"><i class="fa fa-file"></i><span id="busuanzi_value_page_pv"></span><span></span></span></div></div></footer><i class="fa fa-arrow-up" id="go-up" aria-hidden="true"></i><script src="https://cdn.jsdelivr.net/npm/animejs@latest/lib/anime.min.js"></script><script src="https://cdn.jsdelivr.net/npm/jquery@latest/dist/jquery.min.js"></script><script src="https://cdn.jsdelivr.net/npm/@fancyapps/fancybox@latest/dist/jquery.fancybox.min.js"></script><script src="https://cdn.jsdelivr.net/npm/velocity-animate@latest/velocity.min.js"></script><script src="https://cdn.jsdelivr.net/npm/velocity-ui-pack@latest/velocity.ui.min.js"></script><script src="/js/utils.js?version=1.9.0"></script><script src="/js/fancybox.js?version=1.9.0"></script><script src="/js/sidebar.js?version=1.9.0"></script><script src="/js/copy.js?version=1.9.0"></script><script src="/js/fireworks.js?version=1.9.0"></script><script src="/js/transition.js?version=1.9.0"></script><script src="/js/scroll.js?version=1.9.0"></script><script src="/js/head.js?version=1.9.0"></script><script src="/js/search/local-search.js"></script><script>if(/Android|webOS|iPhone|iPod|iPad|BlackBerry/i.test(navigator.userAgent)) {
  $('#nav').addClass('is-mobile')
  $('footer').addClass('is-mobile')
  $('#top-container').addClass('is-mobile')
}</script><div class="search-dialog" id="local-search"><div class="search-dialog__title" id="local-search-title">本地搜索</div><div id="local-input-panel"><div id="local-search-input"><div class="local-search-box"><input class="local-search-box--input" placeholder="搜索文章"></div></div></div><hr><div id="local-search-results"><div id="local-hits"></div><div id="local-stats"><div class="local-search-stats__hr" id="hr"><span>由</span> <a target="_blank" rel="noopener" href="https://github.com/wzpan/hexo-generator-search" style="color:#49B1F5;">hexo-generator-search</a>
 <span>提供支持</span></div></div></div><span class="search-close-button"><i class="fa fa-times"></i></span></div><div class="search-mask"></div></body></html>